Porous carrier for catalyst comprising metal oxide-coated metal and method of preparing same

Abstract

A porous carrier for a catalyst comprising metal coated with metal oxide grains having a mean grain size of 150 nm or less and a mean pore diameter of 5.5 nm or less, is obtained by subjecting: (a) stainless steel; (b) (i) a metal alkoxide or (ii) a metal alkoxide and a metal acetate salt, both being soluble in alcohols; (c) a diol, cellosolve, or polyether which has coordinating capacity with the (i) metal alkoxide or (ii) metal alkoxide and metal acetate salt and which is soluble in alcohols; and (d) an alcohol solvent to hydrolysis and polycondensation, whereby the stainless steel is coated with an oxygen-containing organic metal compound and, subsequently, heat-treated to form a metal oxide. A method of preparing the catalyst is also provided.

We claim: 
     
       1. A porous carrier for a catalyst comprising a metal coated with metal oxide grains having a mean grain size of 150 nm or less and a mean pore diameter of 5.5 nm or less, obtained by subjecting the following components: (a) stainless steel;   (b) (i) a metal alkoxide or (ii) a metal alkoxide and a metal acetate salt, said (i) metal alkoxide and (ii) metal alkoxide and metal acetate being soluble in alcohols;   (c) a diol, cellosolve, or polyether which has coordinating capacity with said (i) metal alkoxide or (ii) metal alkoxide and metal acetate salt and which is soluble in alcohols; and   (d) an alcohol solvent to hydrolysis and polycondensation, whereby the stainless steel is coated with an oxygen-containing organic metal compound and, thereafter, heat-treated to form a metal oxide.   
     
     
       2. The carrier of claim 1, in which the metal alkoxide is an alkoxide of a metal selected from the group consisting of titanium, aluminum, silica, zirconium, and magnesium. 
     
     
       3. A method of preparing a porous carrier for a catalyst, comprising a metal oxide-coated metal, wherein: (a) stainless steel;   (b) (i) a metal alkoxide or (b) a metal alkoxide and a metal acetate salt, said (i) metal alkoxide and (ii) metal alkoxide and metal acetate being soluble in alcohols;   (c) a diol, cellosolve, or polyether which has a coordinating capacity with said (i) metal alkoxide or (ii) metal alkoxide and metal acetate salt and which is soluble in alcohols; and   (d) an alcohol solvent are:   blended;   water or a water-alcohol mixed solution is added dropwise to the resulting mixture with stirring to form a coating of an oxygen-containing organic metal compound on the surface of the stainless steel;   thereafter, the coated stainless steel is isolated from the reaction mixture, dried, and heat-treated at 300°-1100° C.   
     
     
       4. The method of claim 3, in which, after water or water-alcohol solution has been added dropwise to the reaction mixture with stirring, an alcohol-mixed solution of the substances of (b) and (c) and water or a water-alcohol mixed solution are simultaneously added dropwise with stirring to form a coating of an oxygen-containing organic metal compound on the surface of the stainless steel and, thereafter, the coated stainless steel is isolated from the reaction mixture, dried, and heat-treated at 300°-1100°. 
     
     
       5. A catalyst comprising the porous carrier of claim 1 onto which one or more metals selected from Group Ib and Group VIII of the Periodic Table are deposited. 
     
     
       6. The carrier of claim 1, wherein the metal comprises stainless steel, and the mean grain size of the metal oxide falls within the range of 20-150 nm and the mean pore diameter falls within the range of 3.6-5.5 nm. 
     
     
       7. The carrier of claim 6, wherein the stainless steel is an article having a spherical, flaky, mesh, homogeneous, or plate shape. 
     
     
       8. The method of claim 3, wherein the metal alkoxide is selected from the group consisting of titanium metal alkoxides, aluminum metal alkoxides, silica alkoxides, zirconium metal alkoxides, and magnesium metal alkoxides; the metal acetate salt is selected from the group consisting of magnesium acetate and copper acetate; the diol is selected from the group consisting of 2-methyl-2,4-pentanediol, ethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol; the cellosolve is selected from the group consisting of ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and triethylene glycol monomethyl ether; the polyether is selected from the group consisting of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and triethylene glycol dimethyl ether; and the alcohol solvent is selected from the group consisting of n-propanol, n-butanol, isopropyl alcohol, and ethanol. 
     
     
       9. The carrier of claim 1, onto which is deposited one or more metals selected from the group consisting of Ni, Pd, Co, Fe, Rh, Cu, Ag, and Au.